IRS has had in place for a number of years, rules for tip income. And unless Rush left a cash tip, the full amount of the charged tip would be reported on her W-2.
Back in the day, tips were reported at 8% of total sales or if higher, the reported charge tips. I could be wrong on the numbers, it’s been a couple of decades or so since I waited.
She still might get away with no harassment by the incompetent, felonious, & malicious IRS goons because she's on Team Left.
Not so many years ago, that wouldn't have been true.
Nowadays, in the time of the politicized National Socialist IRS, if she'd waited on George Clooney and donated the tip to the NRA, she'd get an audit notice so fast it would make her head spin...